Balance



Oct. 17, 1961 J. MEIER 3,004,618

' BALANCE Filed Feb. 13, 1958 3 Sheets-Sheet 1 //VVENTOR Johan-n MeierBy WW SQZW (A/21M Abkornegs Oct. 17, 1961 J. MEIER 3,004,618

BALANCE Filed Feb. 13, 1958 3 Sheets-Sheet 2 23 4, Lb\r\\\\\\\\\\\l-jJ\|rI\\ INVENTOR (lo/wank; Meier Aiornegs Oct. 17, 1961 MElER3,004,618

BALANCE Filed Feb. 13, 1958 5 Sheets-Sheet 3 INVENTOR Jokann Meier /Pm 5& J m. A iorheys 3,004,618 BALANCE Johann Meier, Stafa, Switzerland,assignor to Erhard Mettler, Zollikon, Zurich, Switzerland Filed Feb. 13,1958, Ser. No. 715,010 Claims priority, application Switzerland Apr. 13,1957 p 7 Claims. (Cl. 177-248) This invention relates to a balance andmore particularly to a laboratory or analytical balance having one ormore removable ring-shaped weights and an operating device formechanically placing these weights, in position and for lifting-off thesame.

Objects of the invention are to providea balance of the type statedhaving a balance beam, a carrier, said balance beam having a centerknife edge for its support and an outer knife edge for suspension ofsaid carrier therefrom, a ring-shaped weight, supporting means on saidcarrier for horizontally supporting said ring-shaped weight, a pair oflifting-off members which are adapted to make contact with saidring-shaped weight from below at points on opposite sides of its centreof gravity for lifting off said ring-shaped weight from said supportingmeans, an operating device for simultaneously actuating said twolifting-off members, and a stop member disposed above said ring-shapedweight in such manner that said ring-shaped weight in its raisedposition is held between said two lifting-off members and said stopmemher. A further object is to provide a balance of the kind outlinedhaving a carrier suspended from the outer, knife edge of the balancebeam, a set of ring-shaped weights graduated in such manner that any ofsaid weights enclose with clearance the next smaller weight so that asmaller weight may be moved through the ring aperture of the next largerweight, supporting means on said carrier for horizontally supportingsaid ring-shaped weights in a position concentric to one another, a pairof liftingoif members for each of said ring-shaped weights which areadapted to make contact with the respective ringshaped weight frombelowat points onopposite sides-of its centre of gravity for lifting-off saidring-shaped weight from said suspension means, a stop member common forall of said ring-shaped weights and disposed above them in such mannerthat each of said ring-shaped weights in its raised position is heldbetween its two lifting-oif members and said common stop member, aplurality of levers movable about horizontally disposed axes andextending below said set of ring-shaped weights for supporting saidlifting-off members, and an operating device for actuating said leversin order to lift-off or to place on said ring-shaped weights in apredetermined sequence.

These and other objects and the advantages of the invention will best beunderstood from the following description of a specific embodiment whenread in connection with the accompanying drawing, wherein like referencecharacters indicate like parts throughout the figures and in which:

FIGURE 1 is a vertical cross-section of a balance according to theinvention taken on the line 1-1 in FIGS. 2 and 3,

FIGURE '2 is a longitudinal section of the balance, taken on the line 22in FIGS. 1 and 3, and

FIGURE 3 is a horizontal section of the balance, taken on the line 3-3in FIGS. 1 and 2. I

The casing of the balance, not shown in the drawing, encloses within itsupper portion a cast intermediate base plate 4 with upwardly extendingstiffening ribs 5 and 6 and a column 7 which carries a bearing plate 8for the main knife edge 9' of a preferably asymmetrical beam 10. The armof the beam on the right, which is only partly United States Patent3,004,618 Patented Oct. 17,1961

shown, carries a counterpoise which is not illustrated. The left handshorter arm has a knife edge 11 at its end from which is suspended acarrier consisting of two arching stirrup members 16, 17 supported by abearing plate 12 by means of two compensating links 14 and 15, attachedto an intermediate member 13. Members 16, 17 are arranged side by sideand their upper ends 18, 19

are connected by cross members 20, 21 whereas their lower ends arerigidly connected together by another cross member 24. -Attached to thelower cross member 24 is the load carrying hook 26 which projectsthrough an opening in the intermediate base plate 4- and from which thepan 27 is suspended on rods 28.

The free ends of the lower portions 22, 23 of the carrier 16 to 24 arebent outwards beyond the lower cross member 24 in the 'mannerillustrated in FIG. 3 so that they form supports shaped somewhatlike thespokes of a Wheel and adapted to carry concentric ring-shaped weights29, 30, 31, 32. As will be seen'by reference to FIG. 2, the lowerportions 22, 23 are provided with V-shaped notches in which thering-shaped weights 29 to 32 rest horizontally in a predeterminedposition, so that they cannot be laterally displaced. In theillustration according to FIGS. 1 and 2 only the ring-shaped weights 30to 32 are shown resting on the supports 16 to 24, whereas thering-shaped weight 29 has been raised from the supports. For the purposeof thus raising the weights 29 to 32 there are provided, in respect ofeach ring-shaped weight, two lifting fingers. In the drawing the liftingfingers 33, 34 are associated with the ring-shaped weight 29, thelifting fingers 35, 36 with the ring-shaped weight 3%, the liftingfingers 37, 38 with the ring-shaped weight 31, and the lifting fingers39, 40 with the ring-shaped weight 32. The lifting fingers 33 to 40 arethe upwardly bent ends of levers 41 to 48 (FIG. 3) which as such are ofequal length, and all of which extend below the ring-shaped weights 2:9to 32, and are individually pivotable about a common shaft 4-9, As shownin FIG. 2

all the lifting fingers 33 to 40' have V-shaped notches which faceupwardly and which are adapted to support the respective ring-shapedweight in the raised position, as exemplified in the case of weight 29.In its raised position the ring-shaped weight 29 is pressed by the twolifting fingers 33, 34 from below against a stop member 50 located aboveall the ring-shaped weights 29 to 32 and having the shape of a narrowstirrup, bolted by means of anupright shank 51 which rises beyond theperiphery of the largest ring-shaped weight 32, to the intermediate baseplate *4, as shown in FIGS. 1 and 3. FIG. 1 shows that in respect ofeach ring-shaped weight 29 to 32 the stirrup-shaped stop member 50 has aV- shaped notch which opens downward so that any one of the ring-shapedweights that is lifted will be held between the upward V-shaped notchesin the lifting fingers and the downward V-shapcd notch in the stopmember 50, as shown in the case of the ring-shaped weight 29. Since thepoints of contact of the ring-shaped weight 29 with the underside of thestop member 50' are in cross-wise arrangement in relation to the pointsof contact with the upper edges of the lifting fingers 33, 34 thering-shaped weight 29 will be secured against lateral displacement alsowhen it is raised.

If the two levers 41, 42 with their lifting fingers 33, 34 are tilteddown, then thering-shapcd weight 29'will be deposited on the lowerportions 22, 23 of the carrier 16 to 24, the lifting fingers33, 34continuing the downward movement until they reach the same end positionasthat occupied by the other lifting fingers 35 to 40 (FIG. 2) in thedrawing. The satisfactory operation of the arrange-ment that has beendescribed when a ring-shaped I weight is being lifted or loweredpresupposes that the two lifting fingers which lift or lower thering-shaped weight apply themselves to points on the periphery of thering-shaped weight that are as accurately as possible at opposite endsof the same diameter of the ring-shaped weight. During the actuallifting and lowering movement the ring-shaped weight will thentemporarily be in a state of unstable equilibrium. On the other hand, itis an advantage if the raised ring-shaped weight can bear against thestop member 50 at points on a diameter which is preferably at rightangles to the first mentioned diameter, as shown in FIG. 3. If this isthe case the ringshaped weightalthough it may temporarily assume aninclined position on the lifting fingerswill be prevented from slippingout of the notches provided in the stop member and in the liftingfingers.

To permit the levers 41 to 48 and the associated lifting fingers 33 to40 to be rapidly raised and lowered, the lever arms remote from thelifting fingers are acted upon by cam discs 52 to 59 (FIGS. 1 and 3)which are secured to a shaft 60 rotatably mounted in the rib members 5and 6. To ensure that the lifting fingers associated with the samering-shaped weight are actuated in synchronism the cam discs 52 and 53,54 and 55, 5d and 57, and 53 and 59 are pairs of equal shape and securedon the shaft 60 in the same angular positions. Shaft 60 is parallel toshaft 49 and, in the same way as the latter, extends horizontally on oneside of the periphery of the widest ring-shaped weight 32, so that eachset of weights will require anarrangement of very low overall height.The end of shaft 60 which projects from the case of the balance, andwhich is not shown in the drawing, may carry a knob by means of whichthe weights can be deposited, in the sequence determined by thepositions of the cam discs 52 to 59, on the supporting members 22, 23 ofthe carrier, or conversely raised from the same.

To make the illustration clear the upper portion 18 to 21 of the carrieris shown in FIGS. 1 and 2 as being entirely above the stop member 50.However, in order to keep the structural height as low as possible thedescribed balance will in practice be so designed that the stirrupshapedstop member 58 will project between the upper portions 18 and 19 andleave sufficient clearance so that the vertical distance between theupper portions 18, 19 on the one hand, and the lower portions 22, 23 onthe other hand will be accordingly reduced.

While in accordance with the provision of the patent statutes I haveillustrated and described the best forms and embodiments of the presentinvention as now known to me, it will be apparent to those skilled inthe art that other changes and modifications may be made in theapparatus described without deviating from the invention as set forth inthe following claims.

I claim:

1. In a balance apparatus having a base, a balance beam pivotallyconnected to said base by main knife edge means, a carrier suspendedfrom one arm of said balance beam by knife edge suspension means andincluding horizontal supporting means, and a plurality ofconcentrically-arranged spaced annular weight members removablysupported on said horizontal supporting means; the improvement whichcomprises a horizontal stop member secured to said base and extendinghorizontally above and spaced from said supporting means and said weightmembers thereon, said stop member extending diametrically across saidannular weight members and having longitudinally-spaced deformations inthe lower surface thereof above diametrically opposed portions of eachof said weight members, and means sequentially lifting said weightmembers upwardly from said supporting means into engagement respectivelywith the deformations in the lower surface of said stop membercomprising a plurality of pairs of lifting members each arrangedrespectively below one of said annular weights, each pair of saidlifting members being arranged to contact the associated weight memberat diametrically opposed portions thereof, said stop member cooperatingwith said lifting members to hold secure against lateral displacementeach of said ring-shaped weights, when in its raised position, in acrosswise arrangement between said lifting members and said stop member,and operating means sequentially raising said pairs of lifting memberscomprising a plurality of levers pivotally connected to said base andconnected at their ends, respectively, to said lifting members, andmeans pivoting said levers in a predetermined order to sequentially movesaid annular weights vertically.

2. Apparatus as defined in claim 1 wherein each of said lifting membershas an upwardly directed V-shaped notch therein and further wherein thedeformations in said stop member comprise downwardly extending V- shapednotches, said notches cooperating upon upward movement of said liftingmembers to secure the annular weight member clamped therebetween againstlateral displacement.

3. Apparatus as defined in claim 1 wherein each pair of said liftingmembers contacts the associated weight member at diametrically opposedportions lying in a vertical plane normal to said horizontal stopmember, and further wherein said levers are all pivotally movable abouta common horizontal axis which is parallel to said vertical plane andlaterally spaced from said weight members.

4. Apparatus as defined in claim 3 wherein the horizontal supportingmeans of said carrier is connected to the upper portion of said carrierby a vertical portion extending between said common horizontal axis andsaid weight members.

5. The invention as recited in claim 1, wherein said levers can betilted by means of cam discs secured to a common actuating shaftextending horizontally outside the periphery of the widest ring-shapedweight of said set.

6. The invention as recited in claim 1, wherein said lifting members arethe upwardly bent ends of said levers.

7. The invention as recited in claim 1, wherein said levers areindividually tiltable about a common shaft extending horizontallyoutside the periphery of the Widest ring-shaped weight of said set.

References fitted in the file of this patent UNITED STATES PATENTS2,368,655 Fraps Feb. 6, 1945 2,764,400 Mettler Sept. 25, 1956 FOREIGNPATENTS 523,483 Great Britain July 16, 1940 719,985 Great Britain Dec.8, 1954

